I have had this issue a couple of times. In all of my cases, removing the corrupt section corrected the problem. The calculation to find the point of corruption is simple.
convert the video length into seconds. E.g. assume length is 0:9:09;20 then the duration is 549.66667. (Assuming 30 fps)
Multiply the number of seconds by the exact percentage at the point of failure. Assume 34.8% then 549.66667 * 34.8% = 191.284
Convert 191.284 back to Camtasia time format and find that spot in your video and cut it. It may even crash by simply playing that spot.
Hopefully, this helps.